3-D Nanowire Heterostructures from Earth Abundant Materials by Low-cost Fabrication Process for High-efficiency Photoelectrochemical Hydrogen Generation

PI: Wang， deli项目编号：1236155机构：University of California-San diego gotle: D利用地球上丰富的材料制备纳米线异质结构，实现高效光电化学制氢太阳光和海水是地球上最终的可持续能源。它们共同构成了全球能源危机的潜在解决方案，同时可以减少由于使用化石燃料而产生的碳排放。光电化学（PEC）电池利用太阳能直接分解水并产生氢气，这是一种清洁且无碳排放的电池。然而，PEC界普遍认为，在光吸收、水还原、化学稳定性等方面，没有一种材料可以成为太阳能水分解的完美光电极候选者。该项目将研究利用地球上丰富的材料，通过低成本的制造工艺，使用三维（3-D）树状分支纳米线异质结构作为光电极，以实现高效率和潜在的实用和可持续的清洁制氢。树形三维分支纳米线阵列提供了对高效PEC制氢至关重要的理想性能的独特组合，包括增强的光吸收、改进的电荷分离/收集、扩大的表面积和更好的电化学反应动力学。具体来说，建议的研究重点将集中在(i)利用地球丰富的材料（Si, Cu2O， Fe2O3等）通过低成本溶液工艺设计和制造三维纳米结构光电极，（ii）了解纳米线核心和分支之间的界面及其对光生电荷载流子分离和传输的影响，以及（iii）了解电解质/纳米线界面。特别是半导体电极在高局部酸性/碱性条件下的表面电化学反应/腐蚀。化学坚固的材料，如TiO2和WO3也将被研究。该研究将加深对纳米材料和界面中异质结形成的基础材料科学和化学问题的理解，并创建纳米尺度上异质功能集成的新范例。特别是在可再生能源研究方面，这项工作还将在设计和制造高效光伏设备和氢气发电方面发挥作用。此外，该项目将为本科生和研究生提供机会，以获得与该项目相关的跨学科领域的培训。

PI: Wang, DeliProposal Number: 1236155Institution: University of California-San DiegoTitle: D Nanowire Heterostructures from Earth Abundant Materials by Low-cost Fabrication Process for High-efficiency Photoelectrochemical Hydrogen GenerationSunlight and seawater are the ultimate sustainable energy sources on earth. Together they constitute a potential solution to the global energy crisis and at the same time can reduce carbon emission due to the use of fossil fuels. A photoelectrochemical (PEC) cell utilizes solar energy to directly split water and generate hydrogen, which is clean and free of carbon emission. However, it is broadly recognized by the PEC community that there is no single material that can be the perfect photoelectrode candidate for solar water splitting with respect to light absorption, water reduction, chemical stability, etc. This project will investigate the use of three-dimensional (3-D) tree-like branched nanowire heterostructures from earth abundant materials by low-cost fabrication process as photoelectrodes for high efficiency and potentially, a practical and sustainable clean hydrogen generation. The array of the tree-like 3-D branched nanowires offers a unique combination of desired properties that are critical to high efficiency PEC hydrogen generation, including enhanced light absorption, improved charge separation/collection, enlarged surface area, and better electrochemical reaction dynamics. Specifically, the proposed research focus will be on (i) design and fabrication of the 3-D nanostructured photoelectrodes using earth abundant materials (Si, Cu2O, Fe2O3, etc.) by low-cost solution processes, (ii) understanding of the interface between the nanowire core and branches and their effect on separation and transport of the photogenerated charge carriers, and (iii) understanding of the electrolyte/nanowire interface, in particular the surface electrochemical reaction/corrosion of semiconductor electrodes at high local acidic/basic conditions. Chemically robust materials such as TiO2 and WO3 will also be studied. The research will develop an understanding of the fundamental materials science and chemistry questions regarding heterojunctions formation in nanomaterials and interfaces, as well as create a new paradigm of heterogeneous functional integration at nanoscale. Specifically with regard to renewable energy research, this work will also shine a light on design and fabrication/manufacturing of high-efficiency photovoltaic devices and H2 generation. In addition, the project will provide opportunity to the undergraduate and graduate students to obtain training in the interdisciplinary areas related to this project.